Magnetic recording device including magnetic head which includes a stacked body with controlled electrical resistance

ABSTRACT

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic pole and the first magnetic layer, a third magnetic layer provided between the first magnetic pole and the second magnetic layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the second and first magnetic layers, and a third nonmagnetic layer provided between the third and second magnetic layers. The third magnetic layer includes first and second elements. The first and second magnetic layers do not include the second element. Or concentrations of the second element in the first and second magnetic layers are less than in the third magnetic layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2020-095414, filed on Jun. 1, 2020; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments herein generally relate to a magnetic head and a magneticrecording device.

BACKGROUND

Information is recorded in a magnetic recording medium such as a HDD(Hard Disk Drive) or the like by using a magnetic head. It is desirableto increase the recording density of the magnetic recording device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view illustrating a portion of amagnetic recording device according to a first embodiment;

FIG. 2 is a schematic cross-sectional view illustrating the magneticrecording device according to the first embodiment;

FIGS. 3A and 3B are schematic views illustrating characteristics of themagnetic recording device according to the embodiment;

FIGS. 4A to 4C are schematic views illustrating characteristics of themagnetic recording device according to the embodiment;

FIG. 5 is a schematic view illustrating characteristics of the magneticrecording device;

FIG. 6 is a schematic cross-sectional view illustrating a portion of themagnetic recording device according to the first embodiment;

FIG. 7 is a schematic cross-sectional view illustrating a portion of themagnetic recording device according to the first embodiment;

FIG. 8 is a schematic cross-sectional view illustrating a portion of amagnetic recording device according to the second embodiment;

FIG. 9 is a schematic view illustrating characteristics of the magneticrecording device;

FIG. 10 is a schematic cross-sectional view illustrating a portion of amagnetic recording device according to the second embodiment;

FIG. 11 is a schematic cross-sectional view illustrating the magnetichead according to the embodiment;

FIG. 12 is a schematic perspective view illustrating the magneticrecording device according to the embodiment;

FIG. 13 is a schematic perspective view illustrating a portion of themagnetic recording device according to the embodiment;

FIG. 14 is a schematic perspective view illustrating a magneticrecording device according to the embodiment; and

FIGS. 15A and 15B are schematic perspective views illustrating a portionof the magnetic recording device according to the embodiment.

DETAILED DESCRIPTION

According to one embodiment, a magnetic head includes a first magneticpole, a second magnetic pole, and a stacked body provided between thefirst magnetic pole and the second magnetic pole. The stacked bodyincludes a first magnetic layer, a second magnetic layer providedbetween the first magnetic pole and the first magnetic layer, a thirdmagnetic layer provided between the first magnetic pole and the secondmagnetic layer, a first nonmagnetic layer provided between the firstmagnetic layer and the second magnetic pole, a second nonmagnetic layerprovided between the second magnetic layer and the first magnetic layer,and a third nonmagnetic layer provided between the third magnetic layerand the second magnetic layer. The first magnetic layer includes atleast one of Fe, Co, or Ni. The second magnetic layer includes at leastone of Fe, Co, or Ni. The third magnetic layer includes a first elementincluding at least one of Fe, Co, or Ni, and a second element includingat least one selected from the group consisting of Cr, V, Mn, Ti, andSc. The first magnetic layer and the second magnetic layer do notinclude the second element. Or concentrations of the second element inthe first and second magnetic layers are less than a concentration ofthe second element in the third magnetic layer. The first nonmagneticlayer includes at least one selected from the group consisting of Cu,Ag, Au, Al, and Cr. The second nonmagnetic layer includes at least oneselected from the group consisting of Ta, Pt, W, Mo, Ir, Ru, Tb, Rh, Cr,and Pd. The third nonmagnetic layer includes at least one selected fromthe group consisting of Cu, Ag, Au, Al, and Cr.

According to one embodiment, a magnetic head includes a first magneticpole, a second magnetic pole, and a stacked body provided between thefirst magnetic pole and the second magnetic pole. The stacked bodyincludes a first magnetic layer, a second magnetic layer providedbetween the first magnetic pole and the first magnetic layer, a thirdmagnetic layer provided between the first magnetic pole and the secondmagnetic layer, a first nonmagnetic layer provided between the firstmagnetic layer and the second magnetic pole, a second nonmagnetic layerprovided between the second magnetic layer and the first magnetic layer,and a third nonmagnetic layer provided between the third magnetic layerand the second magnetic layer. The first magnetic layer includes a firstelement including at least one of Fe, Co, or Ni, and a second elementincluding at least one selected from the group consisting of Cr, V, Mn,Ti, and Sc. The second magnetic layer includes at least one of Fe, Co,or Ni. The second magnetic layer does not include the second element. Ora concentration of the second element in the second magnetic layer isless than a concentration of the second element in the first magneticlayer. The third magnetic layer includes a third element including atleast one of Fe, Co, or Ni, and a fourth element including at least oneselected from the group consisting of Cr, V, Mn, Ti, and Sc. The secondmagnetic layer does not include the fourth element. Or a concentrationof the fourth element in the second magnetic layer is less than aconcentration of the fourth element in the third magnetic layer. Thefirst nonmagnetic layer includes at least one selected from the groupconsisting of Cu, Ag, Au, Al, and Cr. The second nonmagnetic layerincludes at least one selected from the group consisting of Cu, Ag, Au,Al, and Cr. The third nonmagnetic layer includes at least one selectedfrom the group consisting of Cu, Ag, Au, Al, and Cr.

According to one embodiment, a magnetic recording device includes anyone of the magnetic head described above, a magnetic recording medium,and an electrical circuit. An electrical resistance of the stacked bodyis a first resistance when a current flowing in the stacked body is afirst current. The electrical resistance of the stacked body is a secondresistance when the current flowing in the stacked body is a secondcurrent. The second current is greater than the first current. Thesecond resistance is greater than the first resistance. The electricalresistance of the stacked body oscillates when the current flowing inthe stacked body is a third current. The third current is between thefirst current and the second current. The electrical circuit isconfigured to supply the second current to the stacked body in arecording operation of using the magnetic head to record information inthe magnetic recording medium.

Various embodiments are described below with reference to theaccompanying drawings.

The drawings are schematic and conceptual; and the relationships betweenthe thickness and width of portions, the proportions of sizes amongportions, etc., are not necessarily the same as the actual values. Thedimensions and proportions may be illustrated differently amongdrawings, even for identical portions.

In the specification and drawings, components similar to those describedpreviously or illustrated in an antecedent drawing are marked with likereference numerals, and a detailed description is omitted asappropriate.

First Embodiment

FIG. 1 is a schematic cross-sectional view illustrating a portion of amagnetic recording device according to a first embodiment.

FIG. 2 is a schematic cross-sectional view illustrating the magneticrecording device according to the first embodiment.

As shown in FIG. 2, the magnetic recording device 210 according to thefirst embodiment includes a magnetic head 110 and an electrical circuit20D. The magnetic recording device 210 may include a magnetic recordingmedium 80. For example, the magnetic recording device 210 performs atleast a recording operation. Information is recorded in the magneticrecording medium 80 by using the magnetic head 110 in the recordingoperation.

The magnetic head 110 includes a recording part 60. As described below,the magnetic head 110 may include a reproducing part. The recording part60 includes a first magnetic pole 31, a second magnetic pole 32, and astacked body 20. The stacked body 20 is located between the firstmagnetic pole 31 and the second magnetic pole 32.

For example, the first magnetic pole 31 and the second magnetic pole 32form a magnetic circuit. The first magnetic pole 31 is, for example, amajor magnetic pole. The second magnetic pole 32 is, for example, atrailing shield. The first magnetic pole 31 may be the trailing shield;and the second magnetic pole 32 may be the major magnetic pole.Hereinbelow, the first magnetic pole 31 is taken to be the majormagnetic pole; and the second magnetic pole 32 is taken to be thetrailing shield.

The direction from the magnetic recording medium 80 toward the magnetichead 110 is taken as a Z-axis direction. One direction perpendicular tothe Z-axis direction is taken as an X-axis direction. A directionperpendicular to the Z-axis direction and the X-axis direction is takenas a Y-axis direction. For example, the Z-axis direction corresponds tothe height direction. For example, the X-axis direction corresponds tothe down-track direction. For example, the Y-axis direction correspondsto the cross-track direction. The magnetic recording medium 80 and themagnetic head 110 move relatively along the down-track direction. Amagnetic field (a recording magnetic field) that is generated from themagnetic head 110 is applied to the desired position of the magneticrecording medium 80. The magnetization of the desired position of themagnetic recording medium 80 is controlled to be in a directioncorresponding to the recording magnetic field. Thereby, the informationis recorded in the magnetic recording medium 80.

The direction from the first magnetic pole 31 toward the second magneticpole 32 is taken as a first direction D1. The first direction D1substantially corresponds to the X-axis direction. The first directionD1 may be tilted at a small angle with respect to the X-axis direction.

A coil 30 c is provided as shown in FIG. 2. In the example, a portion ofthe coil 30 c is between the first magnetic pole 31 and the secondmagnetic pole 32. A shield 33 is provided in the example. The firstmagnetic pole 31 is between the shield 33 and the second magnetic pole32 in the X-axis direction. Another portion of the coil 30 c is betweenthe shield 33 and the first magnetic pole 31. An insulating portion 30 iis provided between these multiple components.

As shown in FIG. 2, a recording current Iw is supplied from a recordingcircuit 30D to the coil 30 c. A recording magnetic field thatcorresponds to the recording current Iw is applied from the firstmagnetic pole 31 to the magnetic recording medium 80.

As shown in FIG. 2, the first magnetic pole 31 includes a medium-facingsurface 30F. The medium-facing surface 30F is, for example, an ABS (AirBearing Surface). For example, the medium-facing surface 30F faces themagnetic recording medium 80. For example, the medium-facing surface 30Fis along the X-Y plane.

As shown in FIG. 2, the electrical circuit 20D is electrically connectedto the stacked body 20. In the example, the stacked body 20 iselectrically connected to the first and second magnetic poles 31 and 32.A first terminal T1 and a second terminal T2 are provided in themagnetic head 110. The first terminal T1 is electrically connected tothe stacked body 20 via first wiring W1 and the first magnetic pole 31.The second terminal T2 is electrically connected to the stacked body 20via second wiring W2 and the second magnetic pole 32. For example, acurrent (e.g., a direct current) is supplied from the electrical circuit20D to the stacked body 20.

As shown in FIG. 1, the stacked body 20 includes a first magnetic layer21, a second magnetic layer 22, a third magnetic layer 23, a firstnonmagnetic layer 41, a second nonmagnetic layer 42, and a thirdnonmagnetic layer 43. A fourth nonmagnetic layer 44 is provided in theexample.

The second magnetic layer 22 is located between the first magnetic pole31 and the first magnetic layer 21. The third magnetic layer 23 islocated between the first magnetic pole 31 and the second magnetic layer22. The first nonmagnetic layer 41 is located between the first magneticlayer 21 and the second magnetic pole 32. The second nonmagnetic layer42 is located between the second magnetic layer 22 and the firstmagnetic layer 21. The third nonmagnetic layer 43 is located between thethird magnetic layer 23 and the second magnetic layer 22. When thefourth nonmagnetic layer 44 is provided, the fourth nonmagnetic layer 44is located between the first magnetic pole 31 and the third magneticlayer 23.

The first magnetic layer 21 includes at least one of Fe, Co, or Ni. Thesecond magnetic layer 22 includes at least one of Fe, Co, or Ni. Forexample, the first magnetic layer 21 and the second magnetic layer 22have positive spin polarization.

The third magnetic layer 23 includes a first element and a secondelement. The first element includes at least one of Fe, Co, or Ni. Thesecond element includes at least one selected from the group consistingof Cr, V, Mn, Ti, and Sc. The second element is, for example, an addedelement. The ratio (e.g., the concentration) of the second element inthe third magnetic layer 23 is, for example, not less than 1 atomic %and not more than 80 atomic %. For example, the third magnetic layer 23has negative spin polarization.

The first magnetic layer 21 and the second magnetic layer 22substantially do not include the second element described above. Or, theconcentrations of the second element in the first and second magneticlayers 21 and 22 are less than the concentration of the second elementin the third magnetic layer 23.

The first nonmagnetic layer 41 includes, for example, at least oneselected from the group consisting of Cu, Ag, Au, Al, and Cr. Forexample, the first nonmagnetic layer 41 functions as a layer thattransfers polarized spin.

The second nonmagnetic layer 42 includes, for example, at least oneselected from the group consisting of Ta, Pt, W, Mo, Ir, Ru, Tb, Rh, Cr,and Pd. For example, the second nonmagnetic layer 42 functions as alayer that attenuates polarized spin.

The third nonmagnetic layer 43 includes at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr. For example, the thirdnonmagnetic layer 43 functions as a layer that transfers polarized spin.

The fourth nonmagnetic layer 44 includes at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr. For example, the fourthnonmagnetic layer 44 functions as a layer that transfers polarized spin.

As shown in FIG. 1, for example, a current jc1 that is supplied from theelectrical circuit 20D (referring to FIG. 2) to the stacked body 20 hasan orientation from the second magnetic pole 32 toward the firstmagnetic pole 31. The current jc1 has an orientation from the firstmagnetic layer 21 toward the second magnetic layer 22. An electroncurrent je1 has an orientation from the first magnetic pole 31 towardthe second magnetic pole 32.

For example, when the current jc1 is not supplied to the stacked body20, the orientation of the magnetization of the first magnetic layer 21is substantially the same as the orientation of the magnetization of thefirst magnetic pole 31 and the orientation of the magnetization of thesecond magnetic pole 32. A portion of the magnetic field (the recordingmagnetic field) emitted from the first magnetic pole 31 is orientedtoward the magnetic recording medium 80. On the other hand, anotherportion of the magnetic field (the recording magnetic field) emittedfrom the first magnetic pole 31 passes through the stacked body 20 andenters the second magnetic pole 32 without being oriented toward themagnetic recording medium 80. Therefore, the proportion of the recordingmagnetic field emitted from the first magnetic pole 31 that is orientedtoward the magnetic recording medium 80 is low.

When the current jc1 is supplied to the stacked body 20, the orientationof the magnetization of the first magnetic layer 21 is reversed withrespect to the orientation of the magnetization of the first magneticpole 31 and the orientation of the magnetization of the second magneticpole 32. Therefore, the magnetic field (the recording magnetic field)that is emitted from the first magnetic pole 31 is not easily orientedtoward the stacked body 20. Therefore, the proportion of the recordingmagnetic field emitted from the first magnetic pole 31 that is orientedtoward the magnetic recording medium 80 is high compared to when thecurrent jc1 is not supplied to the stacked body 20. The recordingmagnetic field that is emitted from the first magnetic pole 31 iseffectively applied to the magnetic recording medium 80.

This phenomenon becomes more pronounced as the distance (the recordinggap) between the first magnetic pole 31 and the second magnetic pole 32is reduced. By using such a stacked body 20, good recording can beperformed even when the recording gap is small. According to the firstembodiment, the recording gap at which good recording is possible can bereduced. According to the first embodiment, a magnetic recording devicecan be provided in which the recording density can be increased.

On the other hand, in MAMR (Microwave Assisted Magnetic Recording), therecording is performed by locally controlling the magnetic properties ofthe magnetic recording medium 80 by applying, to the magnetic recordingmedium 80, a high frequency magnetic field generated from a stacked bodyincluding multiple magnetic layers. In MAMR, the high frequency magneticfield is generated by the oscillations of the magnetizations of themagnetic layers.

Conversely, according to the embodiment, the magnetization of the firstmagnetic layer 21 reverses with respect to the magnetization of thefirst magnetic pole 31 and the magnetization of the second magnetic pole32. The magnetic field that is emitted from the first magnetic pole 31is efficiently applied to the magnetic recording medium 80 by anoperation that is different from MAMR.

An example of characteristics of the magnetic head 110 according to theembodiment will now be described.

FIGS. 3A and 3B are schematic views illustrating characteristics of themagnetic recording device according to the embodiment.

These figures schematically show the relationship between the electricalresistance of the stacked body 20 and the magnitude of the current jc1flowing in the stacked body 20 according to the embodiment. In thesefigures, the horizontal axis is the magnitude of the current jc1. Thevertical axis of FIG. 3A is an electrical resistance Rx1 of the stackedbody 20.

As shown in FIG. 3A, the electrical resistance Rx1 increases as thecurrent jc1 increases. As shown in FIG. 3A, the magnitude of the currentjc1 can be separated into a first current range ir1, a second currentrange ir2, and a third current range ir3. The third current range ir3 isbetween the first current range ir1 and the second current range ir2.

In the first and second current ranges ir1 and ir2, the electricalresistance Rx1 changes as a quadratic function of the magnitude of thecurrent jc1. It is considered that this is caused by the temperature ofthe stacked body 20 increasing as the current jc1 increases.

The change of the electrical resistance Rx1 in the third current rangeir3 is different from the effect of the temperature increase. It isconsidered that the change of the electrical resistance Rx1 in the thirdcurrent range ir3 is due to a magnetoresistance effect based on thereversal rates of the magnetizations of the magnetic layers.

FIG. 3B shows the relationship between an electrical resistance Rx2 andthe magnitude of the current jc1, in which the change of the quadraticfunction (the effect of the temperature) of FIG. 3A has been removed.When the effect of the quadratic function is removed as shown in FIG.3B, the electrical resistance Rx2 is substantially constant in the firstcurrent range ir1. Or, compared to the third current range ir3, theelectrical resistance Rx2 gradually changes in the first current rangeir1. The electrical resistance Rx2 changes in the third current rangeir3. The electrical resistance Rx2 is substantially constant in thesecond current range ir2. Or, compared to the third current range ir3,the electrical resistance Rx2 gradually changes in the second currentrange ir2.

For example, as shown in FIG. 3B, the electrical resistance Rx2 of thestacked body 20 is a first resistance R1 when the current jc1 flowing inthe stacked body 20 is a first current i1. The first current i1 is inthe first current range ir1.

As shown in FIG. 3B, the electrical resistance Rx2 of the stacked body20 is a second resistance R2 when the current jc1 flowing in the stackedbody 20 is a second current i2. The second current i2 is greater thanthe first current i1. The second current i2 is in the second currentrange ir2. The second resistance R2 is greater than the first resistanceR1.

The electrical resistance Rx2 of the stacked body 20 is a thirdresistance R3 at a third current i3 that is between the first current i1and the second current i2. The third current i3 is in the third currentrange ir3.

For example, the electrical resistance Rx2 substantially does notoscillate when the current jc1 is the first or second current i1 or i2.For example, the electrical resistance Rx2 oscillates when the currentjc1 is the third current i3. The first current i1, the second currenti2, and the third current i3 have orientations from the first magneticlayer 21 toward the second magnetic layer 22.

FIGS. 4A to 4C are schematic views illustrating characteristics of themagnetic recording device according to the embodiment.

These figures illustrate signals on which FFT (Fast Fourier Transform)processing of a portion of the signal of the electrical resistance Rx2is performed. The signal of the electrical resistance Rx2 includes acomponent (a high frequency component) that temporally changes, and acomponent (the component of the temporal average value) thatsubstantially does not change temporally. The temporally-changingcomponent of the electrical resistance Rx2 is processed by the FFTprocessing. In these figures, the horizontal axis is a frequency ff. Thevertical axis is an intensity Int of the signal. FIG. 4A corresponds towhen the current jc1 is the first current i1. FIG. 4B corresponds towhen the current jc1 is the third current i3. FIG. 4C corresponds towhen the current jc1 is the second current i2.

As shown in FIG. 4B, when the current jc1 is the third current i3, apeak p1 is observed at one frequency fp1. The peak corresponds to a highfrequency oscillation being generated by the stacked body 20.

As shown in FIGS. 4A and 4C, the peak p1 is not distinctly observed whenthe current jc1 is the first or second current i1 or i2. For thesecurrents, a magnetization oscillation that is effective for MAMR issubstantially not generated.

Thus, the electrical resistance Rx2 of the stacked body 20 oscillateswhen the current jc1 flowing in the stacked body 20 is the third currenti3 that is between the first current it and the second current i2.

According to the embodiment, the recording operation is performed usingthe stacked body 20 that has such characteristics.

According to the embodiment, the electrical circuit 20D is configured tosupply the second current i2 described above to the stacked body 20 inthe recording operation of using the magnetic head 110 to record theinformation in the magnetic recording medium 80. Compared to when therecording operation is performed without supplying the second currenti2, the amount of the recording magnetic field oriented from the firstmagnetic pole 31 toward the magnetic recording medium 80 can beincreased by performing the recording operation of supplying therecording current Iw from the recording circuit 30D to the coil whilesupplying a second current i2 such as that described above. Therecording gap at which good recording is possible can be reduced.According to the embodiment, a magnetic recording device can be providedin which the recording density can be increased.

An example of characteristics of a magnetic recording device will now bedescribed.

FIG. 5 is a schematic view illustrating characteristics of the magneticrecording device.

FIG. 5 illustrates simulation results of characteristics of a magnetichead including the stacked body 20 having a first condition CH1, asecond condition CH2, and a third condition CH3. As the first conditionCH1, the configuration of the magnetic head 110 described above isapplied. Namely, for example, the second nonmagnetic layer 42 is Ta; andthe second nonmagnetic layer 42 attenuates polarized spin.

As the second condition CH2, for example, the second nonmagnetic layer42 is Cu; and the second nonmagnetic layer 42 transfers polarized spin.Otherwise, the configuration of the second condition CH2 is similar tothe configuration of the first condition CH1.

As the third condition CH3, the second nonmagnetic layer 42 is notprovided, and the first magnetic layer 21 and the second magnetic layer22 contact each other. Otherwise, the configuration of the thirdcondition CH3 is similar to the configuration of the first conditionCH1.

The horizontal axis of FIG. 5 is a time tm. The polarity of therecording current Iw reverses at a first time t1. The vertical axis ofFIG. 5 is a parameter P1 corresponding to the reversal amount of themagnetization. The parameter P1 corresponds to the reversal amount of amagnetization existing between the first magnetic pole 31 and the secondmagnetic pole 32 for the first to third conditions CH1, CH2, and CH3.

FIG. 5 also illustrates a characteristic PM of the orientation of themagnetization of the first magnetic pole 31. For the characteristic PM,the parameter P1 corresponds to the orientation of the magnetization ofthe first magnetic pole 31. In the example of FIG. 5, the polarity ofthe recording current Iw reverses at the first time t1 (when the time tmis 0.60 ns). When the time tm is 0.62 ns, the orientation of themagnetization of the first magnetic pole 31 starts to change. When thetime tm is 0.67 ns, the change of the orientation of the magnetizationof the first magnetic pole 31 substantially ends.

As shown in FIG. 5, the absolute value of the parameter P1 is small forthe second condition CH2. For the second condition CH2, a magnetizationthat exists between the first magnetic pole 31 and the second magneticpole 32 does not distinctly reverse with respect to the magnetization ofthe first magnetic pole 31.

For the first condition CH1 and the third condition CH3 as shown in FIG.5, it can be seen that a magnetization that exists between the firstmagnetic pole 31 and the second magnetic pole 32 substantially reverseswith respect to the magnetization of the first magnetic pole 31. Thechange of the parameter P1 for the first condition CH1 is faster thanthe change of the parameter P1 for the third condition CH3. A fastmagnetization reversal is obtained for the first condition CH1. For thefirst condition CH1, a high responsiveness with respect to the change ofthe magnetization of the first magnetic pole 31 is obtained because themagnetization of the first magnetic layer 21 quickly changes. For thefirst condition CH1, for example, the BER (Bit Error Rate) can beeffectively reduced in practical conditions of use.

According to the first embodiment, the BER can be effectively reduced,and the recording gap at which good recording is possible can bereduced. According to the embodiment, a magnetic recording device can beprovided in which the recording density can be increased.

According to the embodiment, a high recording capacity in a high-speedrecording operation at a high frequency can be obtained. The recordingdensity can be more effectively improved.

FIG. 6 is a schematic cross-sectional view illustrating a portion of themagnetic recording device according to the first embodiment.

FIG. 6 illustrates the magnetic head 110.

As shown in FIG. 6, the first magnetic layer 21 has a thickness t21. Thesecond magnetic layer 22 has a thickness t22. The third magnetic layer23 has a thickness t23. The first nonmagnetic layer 41 has a thicknesst41. The second nonmagnetic layer 42 has a thickness t42. The thirdnonmagnetic layer 43 has a thickness t43. The fourth nonmagnetic layer44 has a thickness t44. These thicknesses are lengths along the firstdirection D1. As described above, the first direction D1 may be obliqueto the X-axis direction.

In the magnetic head 110, the thickness t21 of the first magnetic layer21 is, for example, not less than 2 nm and not more than 10 nm. Becausethe thickness t21 is not less than 2 nm, for example, the magnetic fieldthat is oriented toward the magnetic recording medium 80 can beeffectively increased. Because the thickness t21 is not more than 8 nm,for example, an efficient magnetization reversal is easily obtained.

In the magnetic head 110, the thickness t22 of the second magnetic layer22 is, for example, not less than 2 nm and not more than 4 nm. When thethickness t22 is not less than 2 nm, a higher gain is easily obtained ina high-speed operation. Because the thickness t22 is not more than 4 nm,stable operations are easily obtained.

In the magnetic head 110, the thickness t23 of the third magnetic layer23 is, for example, not less than 2 nm and not more than 5 nm. When thethickness t23 is not less than 2 nm, for example, the electrons thatpass through the third magnetic layer 23 easily spin. Because thethickness t23 is not more than 5 nm, for example, the magnetization ofthe third magnetic layer 23 easily stabilizes.

In the magnetic head 110, the thickness t41 of the first nonmagneticlayer 41 is, for example, not less than 1 nm and not more than 5 nm.When the thickness t41 is in this range, for example, the electrons thatare spin-polarized by the second magnetic pole 32 easily reach the firstmagnetic layer 21.

In the magnetic head 110, the thickness t42 of the second nonmagneticlayer 42 is, for example, not less than 1 nm and not more than 5 nm.Because the thickness t42 is in this range, for example, a higher gainis easily obtained.

In the magnetic head 110, the thickness t43 of the third nonmagneticlayer 43 is, for example, not less than 1 nm and not more than 5 nm.Because the thickness t43 is in this range, for example, themagnetization of the second magnetic layer 22 and the magnetization ofthe third magnetic layer 23 are easily mutually-stabilized.

In the magnetic head 110, the thickness t44 of the fourth nonmagneticlayer 44 is, for example, not less than 1 nm and not more than 5 nm.Because the thickness t44 is in this range, for example, themagnetization of the third magnetic layer 23 easily stabilizes.

According to the embodiment, for example, the first nonmagnetic layer 41contacts the first magnetic layer 21 and the second magnetic pole 32.For example, the second nonmagnetic layer 42 contacts the secondmagnetic layer 22 and the first magnetic layer 21. For example, thethird nonmagnetic layer 43 contacts the third magnetic layer 23 and thesecond magnetic layer 22. For example, the fourth nonmagnetic layer 44contacts the first magnetic pole 31 and the third magnetic layer 23.

FIG. 7 is a schematic cross-sectional view illustrating a portion of themagnetic recording device according to the first embodiment.

As shown in FIG. 7, the fourth nonmagnetic layer 44 is not provided in amagnetic head 111 according to the first embodiment. In the magnetichead 111, the first magnetic pole contacts the third magnetic layer 23.Otherwise, the configuration of the magnetic head 111 may be similar tothe configuration of the magnetic head 110.

In the magnetic head 111 as well, a fast magnetization reversal isobtained. The BER can be effectively reduced, and the recording gap atwhich good recording is possible can be reduced. According to theembodiment, a magnetic recording device can be provided in which therecording density can be increased.

In the magnetic head 110 and the magnetic head 111, it is favorable forthe third nonmagnetic layer 43 to include Cr. Thereby, for example, themagnetization of the second magnetic layer 22 stabilizes more easily.

Second Embodiment

An example according to a second embodiment will now be described. Inthe following description, a description of portions similar to thefirst embodiment is omitted as appropriate.

FIG. 8 is a schematic cross-sectional view illustrating a portion of amagnetic recording device according to the second embodiment.

As shown in FIG. 8, the magnetic recording device 210 according to thesecond embodiment includes a magnetic head 120, the magnetic recordingmedium 80, and the electrical circuit 20D (referring to FIG. 2). In themagnetic head 120 as well, the stacked body 20 includes the firstmagnetic layer 21, the second magnetic layer 22, the third magneticlayer 23, the first nonmagnetic layer 41, the second nonmagnetic layer42, and the third nonmagnetic layer 43. The fourth nonmagnetic layer 44is provided in the example. In the magnetic head 120 as well, the secondmagnetic layer 22 is located between the first magnetic pole 31 and thefirst magnetic layer 21. The third magnetic layer 23 is located betweenthe first magnetic pole 31 and the second magnetic layer 22. The firstnonmagnetic layer 41 is located between the first magnetic layer 21 andthe second magnetic pole 32. The second nonmagnetic layer 42 is locatedbetween the second magnetic layer 22 and the first magnetic layer 21.The third nonmagnetic layer 43 is located between the third magneticlayer 23 and the second magnetic layer 22. When the fourth nonmagneticlayer 44 is provided, the fourth nonmagnetic layer 44 is located betweenthe first magnetic pole 31 and the third magnetic layer 23.

In the magnetic head 120, the first magnetic layer 21 includes the firstelement that includes at least one of Fe, Co, or Ni, and includes thesecond element that includes at least one selected from the groupconsisting of Cr, V, Mn, Ti, and Sc. For example, the first magneticlayer 21 has negative polarization. The concentration of the secondelement in the first magnetic layer 21 is, for example, not less than 1atomic % and not more than 80 atomic %.

In the magnetic head 120, the second magnetic layer 22 includes at leastone of Fe, Co, or Ni. The second magnetic layer 22 substantially doesnot include the second element described above. Or, the concentration ofthe second element in the second magnetic layer 22 is less than theconcentration of the second element in the first magnetic layer 21. Forexample, the second magnetic layer 22 has positive polarization.

In the magnetic head 120, the third magnetic layer 23 includes a thirdelement that includes at least one of Fe, Co, or Ni, and includes afourth element that includes at least one selected from the groupconsisting of Cr, V, Mn, Ti, and Sc. For example, the third magneticlayer 23 has negative polarization. The concentration of the fourthelement in the third magnetic layer 23 is, for example, not less than 1atomic % and not more than 80 atomic %. The second magnetic layer 22substantially does not include the fourth element described above. Or,the concentration of the fourth element in the second magnetic layer 22is less than the concentration of the fourth element in the thirdmagnetic layer 23.

In the magnetic head 120, for example, the first nonmagnetic layer 41includes at least one selected from the group consisting of Cu, Ag, Au,Al, and Cr. In the magnetic head 120, for example, the first nonmagneticlayer 41 functions as a layer that transfers polarized spin.

In the magnetic head 120, for example, the second nonmagnetic layer 42includes at least one selected from the group consisting of Cu, Ag, Au,Al, and Cr. In the magnetic head 120, for example, the secondnonmagnetic layer 42 functions as a layer that transfers polarized spin.

In the magnetic head 120, for example, the third nonmagnetic layer 43includes at least one selected from the group consisting of Cu, Ag, Au,Al, and Cr. In the magnetic head 120, for example, the third nonmagneticlayer 43 functions as a layer that transfers polarized spin.

In the magnetic head 120, the fourth nonmagnetic layer 44 may beprovided between the first magnetic pole 31 and the third magnetic layer23. The fourth nonmagnetic layer 44 includes, for example, at least oneselected from the group consisting of Cu, Ag, Au, Al, and Cr. In themagnetic head 120, for example, the fourth nonmagnetic layer 44functions as a layer that transfers polarized spin.

For example, the first nonmagnetic layer 41 may contact the firstmagnetic layer 21 and the second magnetic pole 32. The secondnonmagnetic layer 42 may contact the second magnetic layer 22 and thefirst magnetic layer 21. The third nonmagnetic layer 43 may contact thethird magnetic layer 23 and the second magnetic layer 22. The fourthnonmagnetic layer 44 may contact the first magnetic pole 31 and thethird magnetic layer 23.

In the magnetic head 120 as well, the operations described withreference to FIGS. 3A and 3B may be performed. In the magnetic head 120as well, as shown in FIG. 3B, the electrical resistance Rx2 of thestacked body 20 is the first resistance R1 when the current jc1 flowingin the stacked body 20 is the first current i1. The first current it isin the first current range ir1.

In the magnetic head 120 as well, as shown in FIG. 3B, the electricalresistance Rx2 of the stacked body 20 is the second resistance R2 whenthe current jc1 flowing in the stacked body 20 is the second current i2.The second current i2 is greater than the first current i1. The secondcurrent i2 is in the second current range ir2. The second resistance R2is greater than the first resistance R1.

The electrical resistance Rx2 of the stacked body 20 is the thirdresistance R3 at the third current i3 that is between the first currenti1 and the second current i2. The third current i3 is in the thirdcurrent range ir3.

In the magnetic head 120 as well, for example, the electrical resistanceRx2 substantially does not oscillate when the current jc1 is the firstor second current i1 or i2. For example, the electrical resistance Rx2oscillates when the current jc1 is the third current i3. The firstcurrent i1, the second current i2, and the third current i3 haveorientations from the first magnetic layer 21 toward the second magneticlayer 22.

According to the second embodiment, the electrical circuit 20D isconfigured to supply the second current i2 described above to thestacked body 20 in the recording operation of using the magnetic head120 to record the information in the magnetic recording medium 80.Compared to when the recording operation is performed without supplyingthe second current i2, the amount of the recording magnetic fieldoriented from the first magnetic pole 31 toward the magnetic recordingmedium 80 can be increased by performing the recording operation ofsupplying the recording current Iw from the recording circuit 30D to thecoil while supplying a second current i2 such as that described above.The recording gap at which good recording is possible can be reduced.According to the embodiment, a magnetic recording device can be providedin which the recording density can be increased.

An example of characteristics of a magnetic recording device will now bedescribed.

FIG. 9 is a schematic view illustrating characteristics of the magneticrecording device.

FIG. 9 illustrates simulation results of characteristics of a magnetichead including the stacked body 20 having a fourth condition CH4, afifth condition CH5, and a sixth condition CH6. As the fourth conditionCH4, the configuration of the magnetic head 120 described above isapplied. Namely, for example, the second nonmagnetic layer 42 is Cu; andthe second nonmagnetic layer 42 transfers polarized spin.

As the fifth condition CH5, for example, the second nonmagnetic layer 42is Ta; and the second nonmagnetic layer 42 attenuates polarized spin.Otherwise, the configuration of the fifth condition CH5 is similar tothe configuration of the fourth condition CH4.

As the sixth condition CH6, the second nonmagnetic layer 42 is notprovided, and the first magnetic layer 21 and the second magnetic layer22 contact each other. Otherwise, the configuration of the sixthcondition CH6 is similar to the configuration of the fourth conditionCH4.

The horizontal axis of FIG. 9 is the time tm. The polarity of therecording current Iw reverses at the first time t1 (when the time tm is0.60 ns (referring to FIG. 5)). The vertical axis of FIG. 9 is theparameter P1 that corresponds to the reversal amount of themagnetization. The parameter P1 corresponds to the reversal amount of amagnetization existing between the first magnetic pole 31 and the secondmagnetic pole 32 for the fourth condition CH4, the fifth condition CH5,and the sixth condition CH6.

FIG. 9 also illustrates the characteristic PM of the orientation of themagnetization of the first magnetic pole 31. For the characteristic PM,the parameter P1 corresponds to the orientation of the magnetization ofthe first magnetic pole 31. In the example of FIG. 9, the polarity ofthe recording current Iw reverses at the first time t1 (when the time tmis 0.60 ns). When the time tm is 0.62 ns, the orientation of themagnetization of the first magnetic pole 31 starts to change. When thetime tm is 0.67 ns, the change of the orientation of the magnetizationof the first magnetic pole 31 substantially ends.

As shown in FIG. 9, when the time tm is equal to or greater than 0.7 ns,the parameter P1 is larger for the fourth condition CH4 than for thefifth condition CH5 and the sixth condition CH6. For the fourthcondition CH4, a magnetization that exists between the first magneticpole 31 and the second magnetic pole 32 substantially reverses withrespect to the magnetization of the first magnetic pole 31. For thefourth condition CH4, a magnetic body that has a large magnetizationvolume can be quickly reversed. In particular, for the fourth conditionCH4, the OW (Over Write) characteristic of the magnetic recording can beimproved.

According to the second embodiment, the configuration of the magnetichead 120 described above is applied. For example, even at a relativelyhigh recording frequency, the recording capacity is effectively improvedthereby, and the recording characteristics are improved. According tothe second embodiment, a magnetic recording device can be provided inwhich the recording density can be increased.

In the magnetic head 120, the first to third magnetic layers 21 to 23respectively have the thicknesses t21 to t23 (referring to FIG. 6). Inthe magnetic head 120, the first to fourth nonmagnetic layers 41 to 44respectively have the thicknesses t41 to t44 (referring to FIG. 6).

In the magnetic head 120, the thickness t21 of the first magnetic layer21 is, for example, not less than 2 nm and not more than 10 nm. Becausethe thickness t21 is not less than 2 nm, for example, the magnetic fieldthat is oriented toward the magnetic recording medium 80 can beeffectively increased. Because the thickness t21 is not more than 8 nm,for example, an efficient magnetization reversal is easily obtained.

In the magnetic head 120, the thickness t22 of the second magnetic layer22 is, for example, not less than 2 nm and not more than 4 nm. When thethickness t22 is not less than 2 nm, a higher gain is easily obtained ina high-speed operation. Because the thickness t22 is not more than 4 nm,stable operations are easily obtained.

In the magnetic head 120, the thickness t23 of the third magnetic layer23 is, for example, not less than 2 nm and not more than 5 nm. When thethickness t23 is not less than 2 nm, for example, the electrons thatpass through the third magnetic layer 23 easily have spin polarization.Because the thickness t23 is not more than 5 nm, for example, themagnetization of the third magnetic layer 23 easily stabilizes.

In the magnetic head 120, the thickness t41 of the first nonmagneticlayer 41 is, for example, not less than 1 nm and not more than 5 nm.When the thickness t41 is in this range, for example, the spin can beeffectively transferred.

In the magnetic head 120, the thickness t42 of the second nonmagneticlayer 42 is, for example, not less than 1 nm and not more than 5 nm.When the thickness t42 is in this range, for example, the spin can beeffectively transferred.

In the magnetic head 120, the thickness t43 of the third nonmagneticlayer 43 is, for example, not less than 1 nm and not more than 5 nm.When the thickness t43 is in this range, for example, the spin can beeffectively transferred.

In the magnetic head 120, the thickness t44 of the fourth nonmagneticlayer 44 is, for example, not less than 1 nm and not more than 5 nm.When the thickness t44 is in this range, for example, the spin can beeffectively transferred.

FIG. 10 is a schematic cross-sectional view illustrating a portion of amagnetic recording device according to the second embodiment.

As shown in FIG. 10, the fourth nonmagnetic layer 44 is not provided ina magnetic head 121 according to the second embodiment. In the magnetichead 121, the first magnetic pole 31 contacts the third magnetic layer23. Otherwise, the configuration of the magnetic head 121 may be similarto the configuration of the magnetic head 120.

In the magnetic head 121 as well, a magnetization that exists betweenthe first magnetic pole 31 and the second magnetic pole 32 reverses withrespect to the magnetization of the first magnetic pole 31. A magneticbody that has a large magnetization volume can be quickly reversed.According to the second embodiment, a magnetic recording device can beprovided in which the recording density can be increased.

In the magnetic head 120 and the magnetic head 121, it is favorable forthe second nonmagnetic layer 42 and the third nonmagnetic layer 43 toinclude Cr. For example, the transferred spin amount is more easilyimproved thereby.

An example of the magnetic recording medium 80 and the magnetic headincluded in the magnetic recording device 210 according to theembodiment will now be described. In the description recited below, themagnetic heads (the magnetic heads 110, 111, 120, and 121, etc.) andmodifications of the magnetic heads according to the first and secondembodiments are applicable.

FIG. 11 is a schematic cross-sectional view illustrating the magnetichead according to the embodiment.

In the magnetic head (e.g., the magnetic head 110) according to theembodiment as shown in FIG. 11, the first direction D1 from the secondmagnetic pole 32 toward the first magnetic pole 31 may be oblique to theX-axis direction. The first direction D1 corresponds to the stackingdirection of the stacked body 20. The X-axis direction is along themedium-facing surface 30F of the first magnetic pole 31. The anglebetween the first direction D1 and the medium-facing surface 30F istaken as an angle θ1. The angle θ1 is, for example, not less than 15degrees and not more than 30 degrees. The angle θ1 may be 0 degrees.

When the first direction D1 is oblique to the X-axis direction, thethicknesses of the layers correspond to lengths along the firstdirection D1. The configuration in which the first direction D1 isoblique to the X-axis direction is applicable to any magnetic headaccording to the first or second embodiment.

FIG. 12 is a schematic perspective view illustrating the magneticrecording device according to the embodiment.

As shown in FIG. 12, the magnetic head (e.g., the magnetic head 110)according to the embodiment is used with the magnetic recording medium80. In the example, the magnetic head 110 includes the recording part 60and a reproducing part 70. Information is recorded in the magneticrecording medium 80 by the recording part 60 of the magnetic head 110.The information that is recorded in the magnetic recording medium 80 isreproduced by the reproducing part 70.

The magnetic recording medium 80 includes, for example, a mediumsubstrate 82, and a magnetic recording layer 81 provided on the mediumsubstrate 82. A magnetization 83 of the magnetic recording layer 81 iscontrolled by the recording part 60.

The reproducing part 70 includes, for example, a first reproductionmagnetic shield 72 a, a second reproduction magnetic shield 72 b, and amagnetic reproducing element 71. The magnetic reproducing element 71 islocated between the first reproduction magnetic shield 72 a and thesecond reproduction magnetic shield 72 b. The magnetic reproducingelement 71 is configured to output a signal corresponding to themagnetization 83 of the magnetic recording layer 81.

As shown in FIG. 12, the magnetic recording medium 80 moves relative tothe magnetic head 110 in a medium movement direction 85. The informationthat corresponds to the magnetization 83 of the magnetic recording layer81 is controlled by the magnetic head 110 at any position. Theinformation that corresponds to the magnetization 83 of the magneticrecording layer 81 is reproduced by the magnetic head 110 at anyposition.

FIG. 13 is a schematic perspective view illustrating a portion of themagnetic recording device according to the embodiment.

FIG. 13 illustrates a head slider.

The magnetic head 110 is provided in the head slider 159. The headslider 159 includes, for example, Al₂O₃/TiC, etc. The head slider 159moves relative to the magnetic recording medium while flying over orcontacting the magnetic recording medium.

The head slider 159 has, for example, an air inflow side 159A and an airoutflow side 159B. The magnetic head 110 is located at the side surfaceof the air outflow side 159B of the head slider 159 or the like.Thereby, the magnetic head 110 moves relative to the magnetic recordingmedium while flying over or contacting the magnetic recording medium.

FIG. 14 is a schematic perspective view illustrating a magneticrecording device according to the embodiment.

FIGS. 15A and 15B are schematic perspective views illustrating a portionof the magnetic recording device according to the embodiment.

As shown in FIG. 14, a rotary actuator is used in the magnetic recordingdevice 150 according to the embodiment. A recording medium disk 180 ismounted to a spindle motor 180M. The recording medium disk 180 isrotated in the direction of arrow AR by the spindle motor 180M. Thespindle motor 180M responds to a control signal from a drive devicecontroller. The magnetic recording device 150 according to theembodiment may include multiple recording medium disks 180. The magneticrecording device 150 may include a recording medium 181. The recordingmedium 181 is, for example, a SSD (Solid State Drive). The recordingmedium 181 includes, for example, nonvolatile memory such as flashmemory, etc. For example, the magnetic recording device 150 may be ahybrid HDD (Hard Disk Drive).

The head slider 159 records and reproduces the information recorded inthe recording medium disk 180. The head slider 159 is provided at thetip of a suspension 154 having a thin-film configuration. The magnetichead according to the embodiment is provided at the tip vicinity of thehead slider 159.

When the recording medium disk 180 rotates, the downward pressure due tothe suspension 154 and the pressure generated by the medium-facingsurface (the ABS) of the head slider 159 are balanced. The distancebetween the medium-facing surface of the head slider 159 and the surfaceof the recording medium disk 180 becomes a prescribed fly height.According to the embodiment, the head slider 159 may contact therecording medium disk 180. For example, contact-sliding is applicable.

The suspension 154 is connected to one end of an arm 155 (e.g., anactuator arm). The arm 155 includes, for example, a bobbin part, etc.The bobbin part holds a drive coil. A voice coil motor 156 is providedat the other end of the arm 155. The voice coil motor 156 is one type oflinear motor. The voice coil motor 156 includes, for example, a drivecoil and a magnetic circuit. The drive coil is wound onto the bobbinpart of the arm 155. The magnetic circuit includes a permanent magnetand an opposing yoke. The drive coil is located between the permanentmagnet and the opposing yoke. The suspension 154 includes one end andanother end. The magnetic head is provided at the one end of thesuspension 154. The arm 155 is connected to the other end of thesuspension 154.

The arm 155 is held by ball bearings. The ball bearings are provided attwo locations above and below a bearing part 157. The arm 155 can rotateand slide due to the voice coil motor 156. The magnetic head is movableto any position of the recording medium disk 180.

FIG. 15A illustrates the configuration of a portion of the magneticrecording device and is an enlarged perspective view of a head stackassembly 160.

FIG. 15B is a perspective view illustrating a magnetic head assembly (ahead gimbal assembly (HGA)) 158 that is a portion of the head stackassembly 160.

As shown in FIG. 15A, the head stack assembly 160 includes the bearingpart 157, the head gimbal assembly 158, and a support frame 161. Thehead gimbal assembly 158 extends from the bearing part 157. The supportframe 161 extends from the bearing part 157. The direction in which thesupport frame 161 extends is the reverse of the direction in which thehead gimbal assembly 158 extends. The support frame 161 supports a coil162 of the voice coil motor 156.

As shown in FIG. 15B, the head gimbal assembly 158 includes the arm 155extending from the bearing part 157, and the suspension 154 extendingfrom the arm 155.

The head slider 159 is provided at the tip of the suspension 154. Themagnetic head according to the embodiment is provided in the head slider159.

The magnetic head assembly (the head gimbal assembly) 158 according tothe embodiment includes the magnetic head according to the embodiment,the head slider 159 in which the magnetic head is provided, thesuspension 154, and the arm 155. The head slider 159 is provided at oneend of the suspension 154. The arm 155 is connected to the other end ofthe suspension 154.

The suspension 154 includes, for example, lead wires (not illustrated)for recording and reproducing signals. The suspension 154 may include,for example, lead wires (not illustrated) for a heater that adjusts thefly height. The suspension 154 may include, for example, lead wires (notillustrated) for a spin-transfer torque oscillator, etc. These leadwires are electrically connected to multiple electrodes provided in themagnetic head.

A signal processor 190 is provided in the magnetic recording device 150.The signal processor 190 records and reproduces the signals to and fromthe magnetic recording medium by using the magnetic head. For example,the signal processor 190 is electrically connected to the magnetic headby the input/output lines of the signal processor 190 being connected toelectrode pads of the head gimbal assembly 158.

The magnetic recording device 150 according to the embodiment includes amagnetic recording medium, the magnetic head according to theembodiment, a movable part, a position controller, and a signalprocessor. The movable part causes the magnetic recording medium and themagnetic head to separate, or causes the magnetic recording medium andthe magnetic head to be movable relative to each other in a state ofcontact. The position controller aligns the magnetic head at aprescribed recording position of the magnetic recording medium. Thesignal processor records and reproduces the signals to and from themagnetic recording medium by using the magnetic head.

For example, the recording medium disk 180 is used as the magneticrecording medium described above. The movable part described aboveincludes, for example, the head slider 159. The position controllerdescribed above includes, for example, the head gimbal assembly 158.

Embodiments may include the following configurations (e.g.,technological proposals).

Configuration 1

A magnetic head, comprising:

a first magnetic pole;

a second magnetic pole; and

a stacked body provided between the first magnetic pole and the secondmagnetic pole,

the stacked body including

-   -   a first magnetic layer,    -   a second magnetic layer provided between the first magnetic pole        and the first magnetic layer,    -   a third magnetic layer provided between the first magnetic pole        and the second magnetic layer,    -   a first nonmagnetic layer provided between the first magnetic        layer and the second magnetic pole,    -   a second nonmagnetic layer provided between the second magnetic        layer and the first magnetic layer, and    -   a third nonmagnetic layer provided between the third magnetic        layer and the second magnetic layer,

the first magnetic layer including at least one of Fe, Co, or Ni,

the second magnetic layer including at least one of Fe, Co, or Ni,

the third magnetic layer including

-   -   a first element including at least one of Fe, Co, or Ni, and    -   a second element including at least one selected from the group        consisting of Cr, V, Mn, Ti, and Sc,

the first magnetic layer and the second magnetic layer not including thesecond element, or concentrations of the second element in the first andsecond magnetic layers being less than a concentration of the secondelement in the third magnetic layer,

the first nonmagnetic layer including at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr,

the second nonmagnetic layer including at least one selected from thegroup consisting of Ta, Pt, W, Mo, Ir, Ru, Tb, Rh, Cr, and Pd,

the third nonmagnetic layer including at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr.

Configuration 2

The magnetic head according to Configuration 1, wherein

the third nonmagnetic layer includes Cr.

Configuration 3

A magnetic head, comprising:

a first magnetic pole;

a second magnetic pole; and

a stacked body provided between the first magnetic pole and the secondmagnetic pole,

the stacked body including

-   -   a first magnetic layer,    -   a second magnetic layer provided between the first magnetic pole        and the first magnetic layer,    -   a third magnetic layer provided between the first magnetic pole        and the second magnetic layer,    -   a first nonmagnetic layer provided between the first magnetic        layer and the second magnetic pole,    -   a second nonmagnetic layer provided between the second magnetic        layer and the first magnetic layer, and    -   a third nonmagnetic layer provided between the third magnetic        layer and the second magnetic layer,

the first magnetic layer including

-   -   a first element including at least one of Fe, Co, or Ni, and    -   a second element including at least one selected from the group        consisting of Cr, V, Mn, Ti, and Sc,

the second magnetic layer including at least one of Fe, Co, or Ni,

the second magnetic layer not including the second element, or aconcentration of the second element in the second magnetic layer beingless than a concentration of the second element in the first magneticlayer,

the third magnetic layer including

-   -   a third element including at least one of Fe, Co, or Ni, and    -   a fourth element including at least one selected from the group        consisting of Cr, V, Mn, Ti, and Sc,

the second magnetic layer not including the fourth element, or aconcentration of the fourth element in the second magnetic layer beingless than a concentration of the fourth element in the third magneticlayer,

the first nonmagnetic layer including at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr,

the second nonmagnetic layer including at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr,

the third nonmagnetic layer including at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr.

Configuration 4

The magnetic head according to Configuration 3, wherein

the second nonmagnetic layer and the third nonmagnetic layer include Cr.

Configuration 5

The magnetic head according to any one of Configurations 1 to 4, wherein

the first nonmagnetic layer contacts the first magnetic layer and thesecond magnetic pole,

the second nonmagnetic layer contacts the second magnetic layer and thefirst magnetic layer, and

the third nonmagnetic layer contacts the third magnetic layer and thesecond magnetic layer.

Configuration 6

The magnetic head according to any one of Configurations 1 to 5, wherein

the first magnetic pole contacts the third magnetic layer.

Configuration 7

The magnetic head according to any one of Configurations 1 to 6, wherein

the stacked body further includes a fourth nonmagnetic layer,

the fourth nonmagnetic layer is located between the first magnetic poleand the third magnetic layer, and

the fourth nonmagnetic layer includes at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr.

Configuration 8

The magnetic head according to Configuration 7, wherein

the fourth nonmagnetic layer contacts the first magnetic pole and thethird magnetic layer.

Configuration 9

The magnetic head according to Configuration 7 or 8, wherein

a thickness of the fourth nonmagnetic layer is not less than 1 nm andnot more than 5 nm.

Configuration 10

The magnetic head according to any one of Configurations 1 to 9, wherein

a second current has an orientation from the first magnetic layer towardthe second magnetic layer.

Configuration 11

The magnetic head according to any one of Configurations 1 to 10,wherein

a thickness of the first nonmagnetic layer is not less than 1 nm and notmore than 5 nm.

Configuration 12

The magnetic head according to any one of Configurations 1 to 11,wherein

a thickness of the second nonmagnetic layer is not less than 1 nm andnot more than 5 nm.

Configuration 13

The magnetic head according to any one of Configurations 1 to 12,wherein

a thickness of the third nonmagnetic layer is not less than 1 nm and notmore than 5 nm.

Configuration 14

The magnetic head according to any one of Configurations 1 to 13,wherein

a thickness of the first magnetic layer is not less than 2 nm and notmore than 8 nm.

Configuration 15

The magnetic head according to any one of Configurations 1 to 14,wherein

a thickness of the second magnetic layer is not less than 2 nm and notmore than 5 nm.

Configuration 16

The magnetic head according to any one of Configurations 1 to 15,wherein

a thickness of the third magnetic layer is not less than 2 nm and notmore than 5 nm.

Configuration 17

A magnetic recording device, comprising:

the magnetic head according to any one of Configurations 1 to 16;

a magnetic recording medium; and

an electrical circuit,

an electrical resistance of the stacked body being a first resistancewhen a current flowing in the stacked body is a first current,

the electrical resistance of the stacked body being a second resistancewhen the current flowing in the stacked body is a second current, thesecond current being greater than the first current, the secondresistance being greater than the first resistance,

the electrical resistance of the stacked body oscillating when thecurrent flowing in the stacked body is a third current, the thirdcurrent being between the first current and the second current,

the electrical circuit being configured to supply the second current tothe stacked body in a recording operation of using the magnetic head torecord information in the magnetic recording medium.

According to embodiments, a magnetic head and a magnetic recordingdevice can be provided in which the recording density can be increased.

In the specification of the application, “perpendicular” and “parallel”refer to not only strictly perpendicular and strictly parallel but alsoinclude, for example, the fluctuation due to manufacturing processes,etc. It is sufficient to be substantially perpendicular andsubstantially parallel.

Hereinabove, exemplary embodiments of the invention are described withreference to specific examples. However, the embodiments of theinvention are not limited to these specific examples. For example, oneskilled in the art may similarly practice the invention by appropriatelyselecting specific configurations of components included in magneticrecording devices such as magnetic heads, magnetic poles, secondmagnetic poles, stacked bodies, magnetic layers, nonmagnetic layers,wirings, etc., from known art. Such practice is included in the scope ofthe invention to the extent that similar effects thereto are obtained.

Further, any two or more components of the specific examples may becombined within the extent of technical feasibility and are included inthe scope of the invention to the extent that the purport of theinvention is included.

Moreover, all magnetic recording devices practicable by an appropriatedesign modification by one skilled in the art based on the magneticrecording devices described above as embodiments of the invention alsoare within the scope of the invention to the extent that the spirit ofthe invention is included.

Various other variations and modifications can be conceived by thoseskilled in the art within the spirit of the invention, and it isunderstood that such variations and modifications are also encompassedwithin the scope of the invention.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the invention.

What is claimed is:
 1. A magnetic recording device, comprising: amagnetic head; a magnetic recording medium; and an electrical circuit,the magnetic head, comprising: a first magnetic pole; a second magneticpole; and a stacked body provided between the first magnetic pole andthe second magnetic pole, the stacked body including a first magneticlayer, a second magnetic layer provided between the first magnetic poleand the first magnetic layer, a third magnetic layer provided betweentire first magnetic pole and the second magnetic layer, a firstnonmagnetic layer provided between the fast magnetic layer and thesecond magnetic pole, a second nonmagnetic layer provided between thesecond magnetic layer and the first magnetic layer, and a thirdnonmagnetic layer provided between the third magnetic layer and thesecond magnetic layer, the first magnetic layer including at least oneof Fe, Co, or Ni, the second magnetic layer including at least one ofFe, Co, or Ni, the third magnetic layer including a first elementincluding at least one of Fe, Co, or Ni, and a second element includingat least one selected from the group consisting of Cr, V, Mn, Ti, and S,the first magnetic layer and the second magnetic layer not including thesecond element, or concentrations of the second element in the first andsecond magnetic layers being less than a concentration of the secondelement in the third magnetic layer, the first nonmagnetic layerincluding at least one selected from the group consisting of Cu, Ag, Au,Al, and Cr, the second nonmagnetic layer including at least one selectedfrom the group consisting of Ta Pt, W, Mo, Ir, Ru, Tb, Rh, Cr, and Pd,and the third nonmagnetic layer including at least one selected from thegroup consisting of Cu, Ag, Au, Al, and Cr, an electrical resistance ofthe stacked body being a first resistance when a current flowing in thestacked body is a first current, the electrical resistance of thestacked body being a second resistance when the current flowing in thestacked body is a second current, the second current being greater thanthe first current, the second resistance being greater than the firstresistance, the electrical resistance of the stacked body oscillatingwhen the current flowing in the stacked body is a third current, thethird current being between the first current and the second current,the electrical circuit being configured to supply the second current tothe stacked body in a recording operation of using the magnetic head torecord information in the magnetic recording medium.
 2. The deviceaccording to claim 1, wherein the third nonmagnetic layer includes Cr.3. The device according to claim 1, wherein the first nonmagnetic layercontacts the first magnetic layer and the second magnetic pole, thesecond nonmagnetic layer contacts the second magnetic layer and thefirst magnetic layer, and the third nonmagnetic layer contacts the thirdmagnetic layer and the second magnetic layer.
 4. The device according toclaim 1, wherein the first magnetic pole contacts the third magneticlayer.
 5. The device according to claim 1, wherein the stacked bodyfurther includes a fourth nonmagnetic layer, the fourth nonmagneticlayer is located between the first magnetic pole and the third magneticlayer, and the fourth nonmagnetic layer includes at least one selectedfrom the group consisting of Cu, Ag, Au, Al, and Cr.
 6. The deviceaccording to claim 5, wherein the fourth nonmagnetic layer contacts thefirst magnetic pole and the third magnetic layer.
 7. The deviceaccording to claim 5, wherein a thickness of the fourth nonmagneticlayer is not less than 1 nm and not more than 5 nm.
 8. The deviceaccording to claim 1, wherein the second current has an orientation fromthe first magnetic layer toward the second magnetic layer.
 9. The deviceaccording to claim 1, wherein a thickness of the first nonmagnetic layeris not less than 1 nm and not more than 5 nm.
 10. The device accordingto claim 1, wherein a thickness of the second nonmagnetic layer is notless than 1 nm and not more than 5 nm.
 11. The device according to claim1, wherein a thickness of the third nonmagnetic layer is not less than 1nm and not more than 5 nm.
 12. The device according to claim 1, whereina thickness of the first magnetic layer is not less than 2 nm and notmore than 8 nm.
 13. The device according to claim 1, wherein a thicknessof the second magnetic layer is not less than 2 nm and not more than 5nm.
 14. The device according to claim 1, wherein a thickness of thethird magnetic layer is not less than 2 nm and not more than 5 nm.